Stonehenge is truly an unexplained mystery.  No one knows why it was created or how it was used.  Large, heavy stones came from miles away and were set in a circle in a pattern of large sarsen stones and smaller bluestones.  Some suspect the site was sacred and used for ceremonies.  Some say it was set up to track solar movements.  Scientists have detected other monuments underground in the area.  Others believe aliens built it.  The stones have a bell-like tone when struck so perhaps it was used for festivals.  Scientists believe it took 1500 years to create, beginning around 3000 BCE.  The book presents many points to ponder but offers no answers.  A factsurfer website leads to additional information.  Three books are references along with a glossary and index.